Ben, do think this used to be doable? I have three versions installed at the moment, and could not navigate the menus with the mouse wheel in CC2014.
I wondered if it might be a mouse setting, and I also tried Scroll Lock on and off with no change.
What I was able to do, and which might help you, was having opened a menu and hovered over an item to make it blue, was to navigate entirely with the cursor keys. It seems to me that that would give you fine control. You can also twirl out a group with the right cursor key, or move between menus with the left and right cursor keys.
Does that help at all?
Although not possible given it's current state, from what I remember whenever I accessed a menu that had more entries then could fit by the bottom of the screen, it would reorganize it into a multi-columned list that attempted to fit all the Brushes/Actions/Layer Styles that I had installed.
On a side note, YES I have too many brushes, (266), and YES I need to organize them into groups I just haven't taken the time to do that.
And also YES I know I can use the keyboard to type the first letter of a Brush/Style/etc. to jump to that part of the menu... the problem I run into is the overwhelming majority of my brushes are not named simply like, Bird Brushes 1, Trees 6, Grunge 4, etc. so I can't find them by simply typing in the first digit.
I don't know how hard it would be to add the old menu display method back or just allow the scroll wheel to work like you would expect it to.... but I've been using a scroll wheel to navigate for so long I use it out of force of habit and it kind of frustrated me to the point of making a post about it.
Edit: give me a few minutes I might be able to find an old screenshot of what it used to look like.
Granted, it's a very old version of Photoshop, (CS5) but I believe it was also in version CS6, the precursor to CC if I remember right....
I personally prefer this method since it allows me to see all my brushes at the same time so in the event that I know where to look for the brush I want I don't have to go scrolling through a long list...